The invention concerns a roll-changing pit, which connects a mill hall with a roll workshop, such that a rolling stand with work rolls and back-up rolls is located in the mill hall; and such that a locomotive can move in the roll-changing pit in the axial direction of the work rolls and back-up rolls to transport used back-up rolls or work rolls out of the rolling stand and into the roll workshop or to transport new back-up rolls or work rolls from the roll workshop to the rolling stand.
The invention also concerns a method for changing a set of work rolls in a rolling stand, such as a roughing stand or a finishing stand for rolling plate, which comprises the following steps: supporting the used work rolls of the set of work rolls on each other and then moving the used set of work rolls in the axial direction of the work rolls on the operating side of the rolling stands from a mill hall to a roll workshop by means of a locomotive, which is moved in a roll-changing pit, which connects the mill hall with the roll workshop; and a method for changing a set of back-up rolls in a rolling stand, such as a roughing stand or a finishing stand for rolling plate, which comprises the following steps: insertion of a roll-changing frame between the used lower back-up roll and the used upper back-up roll by means of a locomotive and a connecting rod and then transporting the used set of back-up rolls in the axial direction of the back-up rolls on the operating side of the rolling stands from a mill hall to a roll workshop by means of the locomotive, which is moved in a roll-changing pit, which connects the mill hall with the roll workshop.
A roll-changing pit of this type and methods of this type are disclosed by JP 60-196211.
WO 03/099 479 A1 describes a device for changing pairs of work rolls and/or pairs of back-up rolls in rolling stands, in which the back-up rolls and the work rolls are guided in the housing frame in respective chocks that can be lifted or lowered, and the pair of work rolls can be moved out by a linear actuator while being supported on the chocks. The pair of back-up rolls can be moved in or out by means of a lower back-up roll supported on a track and wheels and a roll-changing frame, which supports the upper back-up roll and is supported on the lower back-up roll. In this regard, the pair of work rolls can be coupled on the drive side of the rolling stand with a hydraulic piston-cylinder actuator that is dimensioned in its stroke length for the removal or installation distance and can be uncoupled when it has been withdrawn the required distance. Furthermore, a roll-changing frame, which has been moved in at a height level between the back-up rolls, can be coupled to the same piston-cylinder actuator, and, when the upper back-up roll and the roll-changing frame are supported on the lower back-up roll, the pair of back-up rolls can be moved out or moved back in. The cited document also describes a corresponding method.
WO 2004/039 512 A1 discloses a tractor, with which the sets of rolls are pulled into a roll workshop (RW) and moved back again. The tractor is moved by gear wheels of the tractor that engage racks.
DE 43 21 663 A1 describes a rolling mill with support plates, which are arranged on the operating side of the rolling stands, are supported on carriages, can be displaced transversely to the roll axes, and are equipped with at least two pairs of rails, which are arranged side by side for receiving sets of work rolls supported on rollers, and with changing pits arranged in front of each rolling stand, with the bottom of each changing pit being equipped with runout rails for sets of back-up rolls. In this regard, the pits are covered between the stands and the support plates with cover plates that extend the length of the pit, which can be fixed in their initial position and can be swiveled out of this initial position to change the back-up rolls, and each cover plate is provided with a . . . for moving out sets of work rolls and transferring them to one of the pairs of tracks of the respective support plates assigned to it.
WO 03/015 949 A1 describes an apparatus for changing work rolls and back-up rolls of a strip rolling mill, in which a roll-changing carriage, which can be displaced transversely to the rolling stand and holds the old sets of rolls that have been removed, makes it possible to replace the old sets of rolls with new sets of rolls. The apparatus consists of a stationary changing cylinder mounted at the floor level of the mill, whose piston rod can move in and out transversely to the rolling stand, and of an extraction carriage connected to the forward end of said piston rod and movable on said roll-changing carriage, said extraction carriage being connectable with said roll-changing carriage such that said extraction carriage and said roll-changing carriage are movable together by said changing cylinder transversely to the longitudinal path of said strip mill. In addition, a side shift cylinder that is independent of the roll-changing carriage can move a side shift table, which is installed in said roll-changing carriage, transversely to the direction of movement of the roll-changing carriage, in order to move the sets of rolls to be changed in or out of a changing position which is aligned with the center of the rolling stand.
WO 2005/089 972 A1 describes a method for changing sets of rolls in rolling stands of a mill train with several rolling stands, each of which has back-up rolls and work rolls, by supporting them on each other and then moving them out in the axial direction of a set of work rolls or a set of back-up rolls on the operating side into a roll workshop and then moving new sets of rolls back and mounting them. During this operation, the sets of worn work rolls transported by a number of separate side shift carriages that corresponds to the number of rolling stands on the operating side are successively moved by a single locomotive on a single connecting track to the roll workshop, and from there the new sets of work rolls are driven back and at changing intervals are set down on the respective side shift carriages between the rolling stands, and after clearance of the operating side by the side shift carriages, after each dismounted worn set of work rolls, the worn back-up rolls are moved out, moved to the roll workshop by crane, serviced, transported back and remounted in the assigned rolling stands. The cited document also describes a device for carrying out this method.
DE 31 23 933 A1 discloses a device for changing the rolls of a rolling stand.
EP 0 911 089 A2 discloses a device and a method for making quick roll changes in a six-high rolling stand.